The Iberian world is peculiarly difficult to fit into a discussion of toleration, because there was in Iberian society no longer any pluralism of culture after the expulsions of the Jews (1492 from Spain, 1497 from Portugal) and the Muslims (1609–14), and therefore no problem of tolerance that might call for either new legislation or new intellectual concepts. The expulsions of these minorities were preceded in each case by impassioned discussions about the rights and wrongs of permitting (that is, tolerating) them within society; thereafter, quite obviously, toleration was not a major issue. But Spain cannot be written off in considering the matter, even though it is habitual to do so. Moreover, the case of Spain allows us to consider in general the interesting differences between northern and Mediterranean Europe, and the reasons for the total absence of toleration theory in the Mediterranean. Spain, Italy and associated states in the Mediterranean were, until the twentieth century, in the forefront of the perennial war against Islamic Africa, a fact that has often been offered as an explanation of Spain's aggressive stance towards non-Christian faiths. Yet there was also a perennial war against Islam in Transylvania and associated border states, which managed none the less to accept some toleration in the sixteenth century; and Italy for long periods tolerated its Jews in a way that the Spaniards since 1492 considered impossible. The Spanish case, evidently, is not easy to explain.

We may consider at least three main aspects of Spanish attitudes in the eighteenth century: retrospective reflections on the country's historical experience; new philosophical approaches; and appreciations of foreign thought.